Stretch blow-molded or thermoformed pouch and a method for making such pouch

ABSTRACT

A stretch blow-molded or thermoformed pouch ( 10 ) comprising a neck with an opening, and a process for making and handling a pouch, comprising—blow molding a preform or thermoforming a sheet or film into a mold to create a pouch with a neck ( 20 ) comprising opening ( 30 ),—removing the pouch from the mold,—transporting the pouch at the neck,—filling the pouch with a product,—closing the pouch.

TECHNICAL FIELD OF THE INVENTION

The present invention relates to a stretch blow-molded or thermoformed pouch.

BACKGROUND OF THE INVENTION

Pouches are well known in the art. Pouches are used as containers for food, beverage and non-food products such as for example cosmetics, fragrances, personal care products, or detergents. Pouches are typically flexible containers which come in multi-dosage or single-dosage forms, and which can be easily discarded after use. Pouches are made of plastic foils or sleeves, or laminates thereof with co-extruded barrier (eg nylon) films, which are welded at the edges. One disadvantage with conventional pouches is however that they easily tear, especially at the welds or at the edges.

It is therefore desirable to provide pouches which do not suffer from this drawback. It is further desired to provide pouches which are cheaper to be processed.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide a stretch-blow molded or thermoformed pouch comprising a neck with an opening.

It is another object of the present invention to provide a process for making and handling said pouch. The process comprises the steps of

-   -   a. blow molding a preform or thermoforming a sheet or film into         a mold to create a pouch with a neck comprising an opening     -   b. removing the pouch from the mold     -   c. transporting the pouch at the neck     -   d. filling the pouch with a product     -   e. closing the pouch

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 shows a cross-section of a pouch according to the present invention.

FIG. 2 shows a cross-section of a preferred embodiment of the pouch of the present invention.

DETAILED DESCRIPTION

As shown in FIG. 1, the present invention relates to a stretch-blow molded or thermoformed pouch 10 comprising a neck 20 with an opening 30.

The wall 40 of the pouch 10 preferably has an average thickness of from about 25 micrometers to about 250 micrometers, preferably from about 50 micrometers to about 200 micrometers, even more preferably from about 50 micrometers to about 75 micrometers, and most preferably from about 60 micrometers to about 70 micrometers. Preferably, the average thickness of the wall 40 is less than about 200 micrometers, preferably less than about 150 micrometers, more preferably less than about 120 micrometers, even more preferably less than about 100 micrometers, even more preferably less than about 75 micrometers, and most preferably less than about 70 micrometers. For determining the average wall thickness of the pouch, the neck of the pouch does not have to be taken into account.

By stretch-blow molding or thermoforming, a pouch is created which is seamless. Because of the absence of seams, the pouch 10 according to the present invention is less prone to rupturing during the manipulation (e.g. during filling), transportation, packaging and handling (by a consumer).

The pouch 10 can be blown in many shapes, and can vary from very flexible (bag-like) to more rigid. In one preferred embodiment, the pouch is a self-supporting stand-up pouch 10, as shown in FIG. 2. In this embodiment, the pouch is blown into a form such that the pouch comprises a base 50 that supports the pouch.

The neck 20 is preferably a cylindrical neck, and can be positioned at various locations. For a stand-up pouch, the neck can be positioned opposite the base, centrally or off-centered (e.g. more towards the side). In one embodiment, the neck is in the form of a spout which facilitates emptying the content of the pouch. The opening 30 can be closed by any means known in the art, such as for example a plastic, screwable cap or a tear-off seal such as for example an aluminum foil glued over the opening 30. In another preferred embodiment, a separate dispenser may be provided which can be connected (e.g. screwed onto) to the neck. As such, the pouch can be used as a refill (e.g. hand soaps).

The pouch can be made in many sizes, with internal volumes preferably ranging from 25 ml to 25 l. However volumes below or above this range may also be envisaged. In one embodiment, the pouch is a single unit-dose pouch.

The pouch of the present invention can be used for containing a variety of products such as food products, beverages, and non-food products. The product can be in a liquid form, gel, paste, flowable powder or solid as long as it can be squeezed or poured out of the pouch.

Examples of food products include, but are not limited thereto, oils, dressings, sauces, cream cheese, dairy products such as yoghurt, purees, fruit mousse, meat, syrups, flakes, muesli, pasta, rice, or nuts.

Examples of beverages include non-alcoholic (milk, juice, water) and alcoholic beverages, carbonated or non-carbonated beverages.

Examples of non-food products include personal care products such as skin or hair care products, toothpaste, bath, shower and washing products such as gels, bath foam, bath pearls, detergents, pharmaceuticals, and the like.

The pouch 10 according to the present invention may further comprise a handle or grip. The handle or grip can be designed in the mold such that it is blown simultaneously with the pouch, and thus seamlessly integrated. Alternatively, a separate handle may be provided which can be attached to the neck.

The pouch 10 can be made by means of stretch-blow molding or by thermoforming.

In the stretch-blow molding process, a thermoplastic material is first molded into a preform typically using injection molding. These preforms are produced with the neck of the pouch, if desired including threads. These performs are packaged and fed later (after cooling) into a reheat stretch blow molding machine. In the stretch blow molding process, the preforms are heated (typically using infrared heaters) above their glass transition temperature, and then blown using high pressure air into pouches using metal blow molds. The preform manufacture and pouch blowing can also be performed in the same machine (single-stage process). Preferably, the stretch ratio of total volume of the preform to the total volume of the pouch is higher than about 7, preferably higher than about 20, more preferably higher than about 25, even more preferably higher than about 30. For very thin walled pouches, the stretch ratio may even be higher than about 40. In a preferred embodiment, the stretch ratio is higher than about 25 and the average wall thickness is less than 120 micrometers, even more preferably the stretch ratio is higher than about 30 and the average wall thickness is less than about 75 micrometers.

Thermoforming is a process where a thermoplastic sheet or film is heated to a high-enough temperature such that it can be stretched into or onto a mold and cooled to a finished shape.

The thermoplastic material, sheet or film can be, but is not limited thereto, polyethylene (PE), polypropylene (PP), polyethylene terephtalate (PET), polycarbonate (PC), polystyrene (PS), polylactic acid (PLA), polyvinylchloride (PVC). A preferred thermoplastic material is polyethylene terephtalate (PET). The aforementioned thermoplastic materials may also be blended with barrier materials such as for example nylon, oxygen scavengers, weakeners or combinations thereof. Alternatively, the pouch 10 made of the thermoplastic material may comprise a barrier coating.

In addition to the benefit of making a pouch which is less prone to rupturing, there is an additional advantage during the filling, handling and packaging of the pouch. Indeed, after the manufacturing of the pouch, the pouch can be manipulated at its neck when the pouch is removed from the mold. As such during the filling, transportation and up to the moment that the pouch is packaged, the pouch can be transported at the neck. This provides full control of the process, and reduces the risk of rupturing during the entire process. Hence, according to another aspect of the present invention, there is provided a process comprising the steps of:

-   -   blow molding a preform or thermoforming a sheet or film into a         mold to create a pouch with a neck comprising an opening     -   removing the pouch from the mold     -   transporting the pouch at the neck to the filling unit     -   filling the pouch with a product     -   closing the pouch

If the pouch is created out of a preform, in one preferred embodiment, the preform manufacture and pouch blowing are performed in a single-stage process, as described hereinbefore.

The closing of the pouch can be done by any means known in the art, such as for example a plastic, screwable cap or a tear-off seal such as for example an aluminum foil glued over the opening.

When the pouch is closed, the pouch is then preferably transported, still at the neck to the packaging unit. As such, the present invention allows for a continuous process with full control of the pouch, which was not possible before.

In preferred embodiments, the starting materials (preform, sheet or film) or the pouch is sanitized, pasteurized or sterilized either before filling (aseptic filling) e.g. by means of bleaching products such as peroxides, or by hot filling of the product wherein the product which is to be contained in the pouch is added at high temperature (i.e. the product itself sanitizes or sterilizes the pouch). In aseptic filling, it may further be preferred to employ aseptic equipment. This allows the pouch to be used for food products requiring a long shelf life such as e.g. milk-based products.

In preferred embodiments, the pouch is decorated. This can be done through conventional printing or labeling processes at the external surface of the pouch. In a preferred embodiment, the pouch can be decorated in the mold (in-mold labeling).

Through thermoforming it is further possible to create a series of pouches, all thermoformed simultaneously and connected to each other e.g at their side walls, wherein the pouches contain the same products or alternatively, contain different products. 

1. A stretch blow-molded or thermoformed pouch comprising a neck with an opening, and a wall.
 2. A pouch according to claim 1, wherein the wall of the pouch has an average thickness of from 25 micrometer to 250 micrometer.
 3. A pouch according to claim 1, wherein the average thickness of the wall is less than 75 micrometer.
 4. A pouch according to claim 1, wherein said pouch is a self-supporting stand-up pouch.
 5. A pouch according to claim 1, wherein said pouch has an internal volume of from 25 ml to 25 l.
 6. A pouch according to claim 1, wherein said pouch is a single unit-dose pouch.
 7. A pouch according to claim 1, comprising a product selected from a food product, a beverage, or a non-food product.
 8. A pouch according to claim 7, wherein said product is a liquid, a paste, a gel, a flowable powder or a solid product.
 9. A pouch according to claim 1 further comprising an integrated grip or handle.
 10. A pouch according to claim 1, wherein said pouch is a stretch-blow molded pouch, and wherein the stretch ratio of total volume of preform to the total volume of pouch is higher than about
 25. 11. A pouch according to claim 10, wherein said stretch ratio is higher than about 30 and wherein the average wall thickness is less than 75 micrometers.
 12. A process for making and handling a pouch, comprising a. blow molding a preform or thermoforming a sheet or film into a mold to create a pouch with a neck comprising an opening, then b. removing the pouch from the mold, then c. transporting the pouch at the neck, then d. filling the pouch with a product, and e. closing the pouch
 13. A process according to claim 12, further comprising the step of transporting the pouch at the neck to a packaging unit.
 14. A process according to claim 12, further comprising a sanitization, sterilisation or pasteurisation step.
 15. A process according to claim 12, further comprising a decoration step. 